Install Instructions

&IGURE 0IPINGTODIAPHRAGMORBLADDEREXPANSIONTANK
Expansion Tank Location
Figures 46 and 47 show typical installation of the system
expansion tank. It is highly recommended that you locate
the air separator and expansion tank as shown in the sug-
gested piping drawings on pages 47 - 49.
Ensure that the expansion tank size will handle boiler and
system water volume and temperature. See tank manu-
facturer’s instructions and ratings for details. Additional
tanks may be added to the system if needed to handle the
expansion. These tanks may be installed by connecting to
tees in the system piping.
Undersized expansion tanks cause system
water to be lost from the relief valve and
makeup water to be added through the fill
valve. Eventual boiler failure can result due
to excessive make-up water addition. Always
locate the cold-water fill connection at the
expansion tank. Never locate this elsewhere.
Diaphragm- or bladder-type tank:
Refer to Figure 48 for suggested piping when using a dia-
phragm- or bladder-type expansion tank.
Diaphragm- or bladder-type expansion
tank—Control fill pressure with the tank air
charge pressure. Always check pressure and
charge tank with tank removed from system
to be sure reading is accurate. Boiler relief
valve is set for 30 PSIG. Operating pressure
of system, after temperature expansion above
cold fill pressure, should not exceed 24 PSIG
to avoid weeping of relief valve.
Install an automatic air vent on top of the air separator, per
separator manufacturer’s instructions.
Part number 550-142-122/0513
42
TM
GAS-FIRED WATER BOILER — Boiler Manual
Primary/Secondary System Piping